In recent years, wireless networks have become increasingly popular. For example, networks including wireless mobile terminals now serve to help automate and expedite processes in retail, manufacturing, warehousing and other industries. In a retail environment, wireless mobile terminals may take the form of a wireless bar code reading device for use in tracking inventory and checking prices. In the warehousing industry, the same mobile terminals may be used to keep accurate accounting of incoming and outgoing shipments. In health care, transportation and other industries, the mobile terminals may take the form of wireless pen based computers to aid with on-site document control procedures, etc.
In order to provide for real time communication, the mobile terminals often include a radio which allows them to communicate with a host computer connected to a LAN, for example. LANs typically allow for connecting of devices operating in a building or specified site. Devices physically connected to the LAN may include desk top computers, printers and host computers. If the LAN also supports wireless mobile terminals such as those mentioned above, the LAN will also have connected thereto one or more access points (sometimes referred to as base stations). Each access point is coupled to the LAN and includes at least one radio through which wireless communication with the mobile terminals can occur.
Each access point can communicate with mobile terminals operating within the cell coverage area of the access point. The cell coverage area is the area in which the access point can reliably communicate with a mobile terminal. Once the mobile terminal roams outside of the cell coverage area of the access point, the mobile terminal can no longer communicate with the LAN through that particular access point. In order to provide cell coverage throughout an entire building or site, a LAN typically includes multiple access points strategically located throughout the building or site. Thus, the combined cell coverage of the access points is sufficient to cover the entire building or site. Mobile terminals may then roam from one area to another within the LAN.
Access points are known which include two radios for improving the reliability of a given wireless LAN. For example, U.S. Pat. No. 5,546,397 to Mahany describes an access point which includes two radios. In a first mode of operation, both radios operate on the same channel to create dual radio diversity. According to a second operating mode, the additional radio serves to monitor transmissions from other access points to confirm proper operation. In a third operating mode, the additional radio in two or more access points form a wireless bridge therebetween in the event of break in the network hardwired infrastructure.
Nevertheless, these conventional access points failed to address many non-reliability related problems. For example, such access points did not provide for simultaneous communications with two or more mobile terminals on respective channels.
Accordingly, there is a strong need with the art for an access point which provides for simultaneous communications with two or more mobile terminals on different channels. Moreover, there is a strong need in the art for an access point which carries out simultaneously different communication functions among the mobile terminals using respective radios. Finally, there is a strong need in the art for an access point which provides flexibility in operation based on the use of two or more radios.